The present invention relates to a powder loading device for transferring powdered material such as powdered food, powdered feed, powdered chemicals, or powdered pharmaceuticals from a powder silo or the like, used for temporary storage, into a boat, a freight car, a truck, or the like.
Many different types of powder, including raw material for food products and industrial applications, are widely used. Large-scale plants use large amounts of powder. Since shipping powder is labor-intensive, various types of powder, which serve as raw materials, are transferred from a truck via air conveyance to a raw powder storage silo for temporary storage. The raw powder materials stored in the silo are sifted and then stored in a product powder storage silo as the powder to be used as the product.
The shipping means, such as a ship, a train, or a truck, departs from a shipping section. The raw powder material or the powder product is stored in an overhead silo. A powder loading device, also known as a loader, is installed in the ceiling of the shipping section to load the raw powder material or the powder product into the shipping means. The following is an overview of a conventional powder loading device used to load powder into trucks.
Referring to FIG. 1, powder, such as raw wheat or bran, is stored in a silo (not shown) at a product or feed plant 500. In general, powder is shipped in a loose state by dropping the powder through an opening at the top of a trailer or a dump truck 502 using a truck loader 501. The powder falls freely from its own weight into the opening of dump truck 502. Truck loader 501 is installed in the ceiling of the first floor of plant 500. A conveyer 503, installed on the third floor of plant 500, moves the powder from the silo to truck loader 501 via a pipeline 504. Truck loader 501 is attached to the ceiling of a truck transport opening 505.
Referring to FIG. 2, eaves 506 project significantly outward from a section of the first floor of plant 500 to provide rain protection over a shipping section 507. An accordion-style extendable chute 509, attached via a loader mounting section 508, is extendable downward. A canvas feed 510, attached on the lower end of extendable chute 509, contains a raw material detection level switch 511.
A motor powering section 512, which controls the extension and contraction of extendable chute 509, is located on a lower surface of loader mounting section 508. A chute connecting pipe 513 connects extendable chute 509 to powder pipeline 504. Powder pipeline 504 extends inside plant 500. A control panel 518 is installed in plant 500 to control the loading of powder.
Dump truck 502 arrives at shipping section 507 of plant 500. A worker operates control panel 518 to move extendable chute 509 downward until canvas feed 510 contacts the bottom of a container 514 on dump truck 502. The worker operates control panel 518 to send powder from pipeline 504 into extendable chute 509 via chute connection pipe 513. Powder flows through extendable chute 509 into container 514 of dump truck 502.
As the powder is loaded into container 514 of dump truck 502, the powder level rises. Powder accumulates inside canvas hood 510, activating raw material detection level switch 511. Motor 512 begins to retract extendable chute 509. The powder left in canvas hood 510 is gravity fed from the lower section of canvas hood 510 into dump truck 502. When canvas hood 510 is empty, raw material detection level switch 511 is deactivated, stopping the retraction of extendable chute 509. The cycle is repeated to load powder into container 514 of dump truck 502.
Truck loader 501 drops powder into dump truck 502 from above to allow loose shipping of the powder. This loading method is especially prone to powder flying out from container 514 of dump truck 502. In order to prevent this flying out of powder, a dust collector 515 (FIG. 1) is attached to the uppermost floor of plant 500. A suction pipe 516, at the suction end of a dust collector 515, terminates inside extendable chute 509, as shown in FIG. 2. A circulation pipe 517 returns dust collected from the outlet end of dust collector 515 back to pipeline 504.
Implementation and installation of the arrangement described above is requires a plant that is large enough to contain the pipes, which must be laid in a particular orientation, and the dust collector, which must be positioned at a relatively high elevation. Even if space is available to install the dust collector and pipes, a large amount of dead space is consumed. If suction from dust collector 515 creates a negative pressure inside extendable chute 509, preparing loose shipment of powder with the door of container 514 left open will result in dust being collected only near the exit opening of extendable chute 509. This complicates collection of particles flying up from inside container 514. Thus, significant amounts of powder can escape from the open section of container 514. Truck loading section 507 of plant 500 is generally open to the outside, with only eaves 506 projecting over truck loading section 507. As a result, when preparing loose shipment of powder, the powder is directly affected by surrounding air currents thereby permitting excessive amounts of powder to escape into the environment. This results in a bad work environment.